Pre-eclampsia is a pregnancy-specific syndrome of unknown etiology, de
fined by clinical findings of elevated blood pressure combined with pr
oteinuria and oedema. The decidual portion of the spiral arteries of w
omen who later develop pre-eclampsia does not undergo the normal pregn
ancy-induced remodelling that converts these vessels to high volume-lo
w resistance conduits. We have postulated that this failure leads to v
ascular spasm, restricted blood flow, placental ischaemia and the rele
ase of toxic substances that enter the maternal circulation, resulting
in multi-organ disease. The complex and interwoven pathways of endocr
ine, paracrine and autocrine factors appear to result in a vicious cyc
le of endothelial cell dysfunction, which is expressed clinically as p
re-eclampsia.